SEM-25: Specifications

General

Modes Simplex, retransmit
Frequency range 26.00-69.95 MHz
Channel spacing 50 kHz
Number of channels 880
Channel selection 44 1-MHz bands, 20 50-kHz channels each
Programmable channels 10
Modulation FM
Operation, including frequency selection Operated from a transceiver-mounted control box, or from a relocatable control box in vehicle (max. cable length 10m)
Transmitter operation

From handset or aux. receiver
From on-board intercom
From telephone remote control

Remote input and output arrangement From telephone remote control over field phone wires, up to 3 km long, max. resistance 480 ohms
Temperature range Operating range from -45°C to +60°C
Overvoltage protector For transients up to 65V from the battery regulator
Power supply 24V battery supply, negative ground, permissible voltage range 21V to 29V, short term overvoltage up to 32V

Modes	Simplex, retransmit
Frequency range	26.00-69.95 MHz
Channel spacing	50 kHz
Number of channels	880
Channel selection	44 1-MHz bands, 20 50-kHz channels each
Programmable channels	10
Modulation	FM
Operation, including frequency selection	Operated from a transceiver-mounted control box, or from a relocatable control box in vehicle (max. cable length 10m)
Transmitter operation	From handset or aux. receiver From on-board intercom From telephone remote control
Remote input and output arrangement	From telephone remote control over field phone wires, up to 3 km long, max. resistance 480 ohms
Temperature range	Operating range from -45°C to +60°C
Overvoltage protector	For transients up to 65V from the battery regulator
Power supply	24V battery supply, negative ground, permissible voltage range 21V to 29V, short term overvoltage up to 32V

Transmitter

Output power High: 15 W
Low: approx. 1 W
Calling frequency 1600 Hz
Audio input

0.25 V from 150 ohm carbon microphone
0 dB from 600 ohm balanced line

Warm-up time approx. 30 seconds

Output power	High: 15 W Low: approx. 1 W
Calling frequency	1600 Hz
Audio input	0.25 V from 150 ohm carbon microphone 0 dB from 600 ohm balanced line
Warm-up time	approx. 30 seconds

Receiver

Sensitivity <= 0.5 µV for 20 dB s/n with 1000 Hz modulation and 10.5 kHz deviation
Bandwidth >= 30 kHz at 6 dB points
Selectivity +/- 50 kHz at 80 dB points
Audio output

0.6 W into 5 ohm loudspeaker
50 mW into 600 ohm headset
1 mW into 600 ohm balanced line

Sensitivity	<= 0.5 µV for 20 dB s/n with 1000 Hz modulation and 10.5 kHz deviation
Bandwidth	>= 30 kHz at 6 dB points
Selectivity	+/- 50 kHz at 80 dB points
Audio output	0.6 W into 5 ohm loudspeaker 50 mW into 600 ohm headset 1 mW into 600 ohm balanced line

Power Supply

Voltage 24V battery (21V to 29V), negative ground, permissible short term overvoltage up to 32V
Power requirements, RX approx. 10 W
Power requirements, TX Low approx. 50 W while transmitting
Power requirements, TX High approx. 80 W while transmitting
Power requirements, TX Low or TX High approx. 29 W when not transmitting

Voltage	24V battery (21V to 29V), negative ground, permissible short term overvoltage up to 32V
Power requirements, RX	approx. 10 W
Power requirements, TX Low	approx. 50 W while transmitting
Power requirements, TX High	approx. 80 W while transmitting
Power requirements, TX Low or TX High	approx. 29 W when not transmitting

Sizes and Weights

Item Height (mm) Width (mm) Depth (mm) Weight (kg)
Control box 174 228 75.5 2.54
Transceiver 222 268 255 14.59
Transceiver mount 120 320 300 9.43
Receiver 222 196 255 11.08
Receiver mount 120 320 230 6.68
Antenna tuning unit 122 290 110 3.70
Overvoltage protector 93 250 126 2.62
Spares case 48 140 140 0.73

Item	Height (mm)	Width (mm)	Depth (mm)	Weight (kg)
Control box	174	228	75.5	2.54
Transceiver	222	268	255	14.59
Transceiver mount	120	320	300	9.43
Receiver	222	196	255	11.08
Receiver mount	120	320	230	6.68
Antenna tuning unit	122	290	110	3.70
Overvoltage protector	93	250	126	2.62
Spares case	48	140	140	0.73

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